Today is World Aids day. Some 33.3m people around the world have the human immunodeficiency virus (HIV) that causes AIDS, according to the latest figures from the United Nations.

Sub-Saharan Africa remains the region most heavily affected by HIV/Aids, although the United Nations Aids programme (UNAIDS) said in a report in September that between 2001 and 2009, new HIV infections fell by more than 25 percent in 22 countries in sub-Saharan Africa.

The key points show:

• 22.5 million people with HIV live in sub-Saharan Africa, around 68% of the global total• An estimated 1.8m people were newly infected with HIV in sub-Saharan Africa in 2009, down from 2.2m in 2001. An estimated 1.3 million people in the region died from Aids-related causes in 2009• Between 2004 and 2009, Aids-related deaths fell by 20% in sub-Saharan Africa• South Africa is home to the world's largest population of HIV-infected people, with 5.6m• With an adult prevalence of 25.9%, Swaziland has the world's most severe level of infection